Ventricular arrhythmias and ischemic disease both alter ventricular wall motion frequently depressing ventricular function. Accordingly, the major focus of this proposed work is to explore the role that regional variations in left ventricular diastolic and systolic function play in regulating normal ventricular filling and systolic function. Using techniques in which regional alterations in shape and transmural variations in strain can be determined, we propose to investigate the ventricular (particularly apical) contributions to normal early diastolic filling. Preliminary results have indicated that there are end systolic volume dependent regional differences in the extent of early diastolic filling and it is the purpose of the proposed studies to investigate the mechnisms responsible for these changes. Other sudies will examine the hypothesis that there are shear strains surrounding dyskinetic areas induced by regional ischemia or abnormal activation of the left ventricular free wall and that the major deformation induced by these changes will depend primarily on the number and direction of the myocardial fibers involved. These studies will provide the first detailed measurements of transmural strain in dyskinetic areas and are designed to address changes in regional function when only portions of the wall thicknes are affected such as subendocardial ischemia due to coronary artery disease. These systolic studies should lend substantial insight into factors governing function and thus oxygen demands in marginally ischemic and dyskinetic myocardium.